Sash and store front construction



Jan. 10, 1939.

c. D. LOWRY SASH AND STORE FRONT CONSTRUCTION Filed April 22, 1938 2 Sheets-Sheet 1 3nnentor CLYDE D. Low/aw.

Jan. 10, 1939. c. D. LOWRY SASH AND STORE FRONT CONSTRUCTION Filed April 22, 1958 2 Sheets-Sheet 2 Zmnentor CLYDE .D. Lou/RY.

attorney Patented Jan. 10, 1939 SASH AND STORE FRONT CONSTRUCTION Clyde D. Lowry,.Toledo, Ohio, assignor to Libbey- Owens-Ford Glass Company, Toledo, Ohio, a

corporation of Ohio Application April 22, 1938, Serial No. 203,473

14 Claims.

The present invention relates to sash and store front constructions and in general has to do with an improved type of metal construction for supporting and holding panes of glass in glazed openings such as, for example, in windows, store fronts, showcases, and the like.

Broadly speaking, the metal sash construction herein provided comprises a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, together with tensioning means for connecting the said sections together and for also effecting the application of the desired pressure upon the glass to secure it in place.

An important object of this invention resides in the provision of improved tensioning means for connecting the stationary and movable sash sections together in such a manner that they will exert a resilient cushioned pressure upon the pane of glass while at the same time permitting relative movement between the said sections to take care of vibration and expansion and contraction of the glass and metal sash construction without disturbing the setting of the pane or causing injury thereto.

Another important object of the invention is the provision of novel tensioning means of the above character wherein the pane of glass, regardless of its thickness, will be subjected to a predetermined amount of clamping pressure, the pressure being so applied and controlled that it is impossible during installation to over-tighten the tensioning means in a way to place the glass under excessive strain such as would result in the breaking or chipping thereof.

Another important object of the invention is the provision of novel tensioning means of the above character embodying a plurality of cooperating adjusting members and spring members, together with positive means for preventing fur-- ther tightening of said adjusting members when said spring members have caused the sash sections to exert a predetermined clamping pressure upon the glass.

Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings wherein like numerals are employed to designate like parts throughout the same:

Fig. l is a front elevation of a sash or store front embodying the present invention;

Fig. 2 is a transverse sectional view through one form of metal sash construction embodying the invention;

Fig. 3 is a detail perspective view of a portion of the tensioning means;

Fig. 4 is a transverse sectional View through another form of sash construction embodying the invention; and

Figs. 5 and 6 are detail sectional views showing a modified tensioning means which may be incorporated in the sash constructions of Figs. 2 and 4 respectively.

In Fig. 1, the numeral I designates, in its entirety, a, glazed opening in which is mounted a pane of glass ll supported in the window opening by the metal sash construction l2 arranged at the top, bottom, and sides of said window. As shown, the building may be faced with stone, Vitrolite, or other ornamental slabs or panels l3 to enhance the appearance thereof.

With reference particularly to that form of the invention illustrated in Figs. 2 and 3, the metal sash construction [2 is mounted on a wooden sill l4 and secured to a wooden back stop l5 carried upon said sill. The sash construction comprises a rear stationary section I6 and a movable front section l'l associated with one another to clamp the pane of glass [8 in position therebetween.

The rear stationary section H5 includes a vertical back wall It which abuts the wooden back stop l5 and is secured thereto by screws or the like 20. Formed integral with the back wall I9 adjacent its upper end is a forwardly directed gutter portion 2! terminating in a substantially vertical lip 22 engaging the inner face of the pane of glass I8, while formed integral with the back wall [9 at the lower end thereof is a forwardly directed, substantially horizontal base plate 23 supported upon the sill I l. Provided adjacent the front end of the base plate 23 is a raised, forwardly extending flange 24 which cooperates with the outer end of said base plate to form a substantially U-shaped channel 25 receiving the lower inturned end 26 of the movable front section 11.

The movable front section I! comprises a face piece 21 provided at its upper end with a lip 28 engaging the outer face of the pane of glass It, said pane being supported at its lower edge upon a plurality of setting blocks which, while not shown, are well known in the art.

Carried by the face piece 2! are a plurality of substantially L-shaped levers 29, each comprising a substantially vertical arm 30 and a substantial- 1y horizontal arm 3| connected together by a fulcrum 32. The vertical arm 30 is secured at its upper end in. a groove 33 formed in said face piece, while the horizontal arm 3| extends rearwardly beneath the pane of glass [8 and is formed at its outer end with an open slot 34. The fulcrum 32 is provided with a series of teeth 35 adapted for selective engagement with the teeth 36 formed on the upper surface of the base plate 23.

The means for tensioning or adjusting the movable section l! to exert the desired clamping pressure upon the pane of glass l8 includes a plurality of cooperating adjusting screws 31 and compression coil springs 38, one adjusting screw 31 and compression spring 38 being associated with each lever 29. Each adjusting screw 3'! consists of a screw-threaded outer end portion which is threaded vertically through the gutter 2!, said screw being provided adjacent its lower end and beneath said gutter with a relatively short hexagonal portion 39 terminating in a pointed end 40. Carried by the adjusting screw directly above the hexagonal portion 39 is a collar 4 I. When the sash construction is properly installed, the compression spring 38 is adapted to encircle the V hexagonal portion of the adjusting screw and to bear at its upper end against the collar 4! and at its lower end against the substantially horizontal arm 3! of the respective lever 29. The inner end 42 of'the slot 34 in said arm 3! is; preferably shaped to correspond to the hexagonal portion 39 of adjusting screw 37.

To install a pane of glass [8 in an opening to be glazed, the rear sash section It is first properly secured in place by the screws: 21!, after which the adjusting screws 3! are associated therewith by threading them upwardly through openings in the gutter 2!. The compression springs 38 are preferably secured at their upper ends to the collars 4|, such as by spot welding or the like, so that the said screws and springs can be associated with the rear section as a unit and in order to prevent the said springs from sliding downwardly off of the screws during the positioning of the front section ll.

Suitable setting blocks are then arranged upon 7 the base plate 23 of the rear section Hi to support the lower edge of the pane of glass. The front section ll, equipped with the desired number of levers 29 (one for each adjusting screw 31) is then associated with the rear section 5,

and this is accomplished by placing the lower in screws 31 are in their uppermost position as in dioated by the full lines in Fig. 2, so that the lower ends thereof are above and out of the way of the arms 3! of levers 29.

When the front section I! has been properly positioned, the teeth 35 of levers 29 will engage the teeth 36 on base plate 23, while the slots 34 in the arms 3l'of levers 29 will be positioned directly beneath the adjusting screws 31. the front section is held in proper position, the adjusting screws are threaded downwardly, with the lower pointed ends 30 thereof passing through the slots 34. As the adjusting screws are tightened down, the springs 38 engaging the arms 3| of levers 29 will be compressed, as shown in broken lines in Fig; 2, and the pressure built up While 'ment of the adjusting screws 31 is limited and a positive means provided for preventing overtightening of said screws. Thus, regardless of the skill of the installation man, excessive pressure cannot be applied to the glass which might result in breakage thereof. This is effected by making the hexagonal portion 33 of the adjusting screw of such diameter in relation to the width of the slot 34 in lever arm 3| that when the saidscrew has been threaded downwardly a. predetermined distance, it will bind in said slot and thus prevented from being further rotated. Consequently, after the strength of the compression spring 38 and the distance the screw 3? is to be threaded downwardly have been once determined, a uniform pressure will always be applied to the glass and over-tightening of the screw prevented. In other words, the construction is such that the operator, when installing the glass, always moves the adjusting screw downwardly as far as he can, since when the spring 38 has been. compressed to the desired extent to cause the sash sections to exert a predetermined pressure upon the glass, the screw will automatically bind in the slot and be prevented from further rotation. In this way, the glass will be held in position by apredeterrnined spring or resilient pressure, and this pressure will be the same whether the glass be one-eighth, onefourth, or three-fourths of an inch in thickness. The compression springs 38 also serve in the capacity of strain or shock absorbers permitting expansion and contraction of the glass and metal, vibrations, etc. without danger of breaking the glass.

In Fig. 4 is illustrated another form of sash construction embodying the principles of the invention described above and which also includes a. rear stationary section 43 and a movable front section 44 associated with one another to clamp the pane of glass 45 in position therebetween. The rear stationary section 43 is supported upon the wooden sill l4 and secured to the wooden back stop l by screws or the like 46 which pass through the vertical back wall 41 of said section. Formed integral with the back wall Al adjacent its upper end is a forwardly directed gutter 48 terminating in a lip 49 engaging the inner face of the pane of glass 45. The stationary section also includes the forwardly extending horizontal base portion 50 resting upon sill l4 and provided adjacent its forward end with an upstanding fulcrum support 5| having upwardly converging side walls 52 and 53 terminating in either a rounded or pointed upper edge 54.

The movable front section 44 comprises a face piece 55 provided at its upper end with a lip 56, engaging the outer face of the pane of glass 45, and at its lower end with an inwardly directed flange 5'! pivotally supported or fulcrurned upon the upper edge 54 of the fulcrum support 5!.

A guard lock mechanism is provided to prevent accidental displacement of the face piece 55 from the fulcrum support 5|. This guard lock is created by the provision of the upstanding rib 58 and flange 59 formed integral with the base portion 53 at opposite sides of the fulcrum support 55, and. in providing said upstanding rib and flange with the inner curved faces 6E! and iii struck on an are from the fulcrum support ill. The inner end face 62 of the inwardly directed flange 51 of face piece 55 and the outer face 63 of said face piece are curved to correspond to the curvature of the faces 6i! and 6! respectively. It will be readily seen that as the face piece 55 is rocked on the fulcrum support 5!, the curved faces 60-52 and (ilfi3 will be in sliding contact with one another so that when the pane of glass is secured in position as hereinafter described, the said face piece cannot be removed from its intended adjustment. Drainage openings M may extend through the base portion 5 to prevent accumulation of water, etc. in the interior of the sash construction.

The means for connecting the front and rear sash sections t3 and 44 together and for exerting the desired clamping pressure upon the glass includes a plurality of substantially rigid lever arms 65 secured at one end within a groove 65 in the face piece 55, said arms extending rearwardly and downwardly and provided at their free inner ends with slots 51 similar to the slots M in lever arms 3! above described.

Threaded through the gutter 48 of the rear section 43 are a plurality of adjusting screws 63 (one for each lever arm 65), each screw being provided at its inner end with a hexagonal portion 69 terminating in a pointed end it! which is adapted to be received. through the slot fil in the respective lever arm 65. Carried by each screw 68 above the hexagonal portion 69 is a collar H and encircling the said hexagonal portion is a compression spring 12 adapted to bear at one end against the collar H and at its opposite end against lever arm 65.

The operation of this form of sash construction is substantially the same as the operation of the sash construction illustrated in Fig. 2. Thus, the rear section 63 is first secured in position by the screws 46, after which the pane of glass 45 is arranged in place against the lip 58 of said rear section and supported at its lower edge upon a plurality of setting blocks 13. The front section 44 is then associated with the rear section it and the said front section rocked in a clockwise direction upon fulcrum support iii to move the lip 56 thereof into engagement with the outer face of the pane of glass. At this time, the adjusting screws 68 are in retracted position, as indicated by the broken lines, but after the front section has been properly located, the screws 68 are threaded inwardly so that the pointed ends it thereof pass through the slots 5'? in lever arms 65.

As the tightening of the adjusting screws is continued, the springs 12 will be compressed and the compression of these springs will cause the front section M to be rocked upon its fulcrum support 5i to force the lip 56 thereof against the pane of glass with the desired pressure. When the springs if have been compressed to the desired extent to cause the sash sections to exert a predetermined clamping pressure upon the glass, the hexagonal portions 69 of the adjusting screws will automatically bind in the slots 61 and further rotation of the said screws by the operator prevented. In this manner, any overtightening of the adjusting screws that might result in glass breakage is effectively prevented.

The compression springs 12 not only function to cause a yielding cushioned pressure to be applied to the glass, but further permit expansion and contraction of the glass and metal as well as vibrations without danger of the glass breaking. In order to obtain a predetermined uniform pressure upon the glass, it is simply necessary to first select a compression spring of the desired strength and to then determine the diameter of the hexagonal portion of the adjusting screw with respect to the width of the slot 61 so that inward movement of the adjusting screw before it binds in the slot will be just enough to compress the said spring to the required extent to give the desired pressure. Thus, a positive means is provided for preventing excessive pressure from being applied to the glass and all of the adjusting screws may be tightened to their maximum limit and without any necessity for discretion on the part of the installation man. Furthermore, it is not necessary for different arrangements to be provided for different thicknesses of sheet, since with the apparatus disclosed the glass will be held in position by a predetermined uniform spring or resilient pressure regardless of the thickness of the sheet.

In Figs. 5 and 6 is illustrated a modified form of tensioning means which may be substituted for the tensioning means in Figs. 2 and 4 respectively, but which operates on the same principle and accomplishes the same purpose. As shown in Fig. 5, the lever 29 is of the same construction as disclosed in Fig. 2, but instead of using coil springs 33, a fiat leaf spring 13 is secured at one end to the fulcrum 32 of each lever and extends rearwardly in spaced, substantially parallel relation to the arm 3!. The outer free end of spring 13 is provided with a slot which registers with the slot 34% in the arm 35 of lever 29. Threaded downwardly through the gutter 28 of the rear stationary section it is an adjusting screw i l provided at its lower end with a pointed hexagonal portion '15 resulting in the formation of a shoulder 16 at the upper end of said pointed portion.

In operation, after the rear section I6 has been secured in place and the movable front section properly associated therewith, the adjusting screws M are threaded downwardly so that the pointed ends 55 thereof pass first through the slots in the springs 13 and then through the slots 3% in the lever arms 3!. Upon continued tightening of the screws, the shoulders 16 thereof engaging springs l3 will bend the same downwardly, and the compression of the springs will rock the levers 29 in a clockwise direction to force the front sash section into clamping engagement with the pane of glass. Tightening of the adjusting screws will be continued until the pointed ends 15 thereof bind in the slots 34 of the levers. When this occurs, further bending of the springs l3 will be prevented. Thus, by a proper selection of springs '53; and by proper regulation of the extent to which the screws i l can be moved downwardly before they in the slots 34, a desired predetermined pressure can be applied to the glass.

The construction illustrated in Fig. 6 is substantially the same as that illustrated in Fig. 5, with the exception that it is applied to the form of sash construction disclosed in Fig. 4. Consequently, a detailed description thereof is not thought to be necessary, except to point out that the principal parts also include a leaf spring ll secured at one end as at '18 to each of the lever arms 55. The spring ii is bent outwardly as at 79 so that the outer end portion thereof is spaced from and normally substantially parallel with the lever arm 65. The adjusting screw is provided with a pointed hexagonal end portion 8| which is adapted to pass through the slot in the spring I? and also through the slot 61 in lever arm 65. The shoulder 82 on adjusting screw 80 engaging spring 1'! will cause the flexing thereof to build up the desired clamping pressure against the pane of glass. This flexing of the spring will continue until the pointed end 8| of the adjusting screw binds in the slot 6'! in lever arm 65, at which time further inward movement of the adjusting screw will be prevented.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a lever arm carried by said movable section, .an adjusting member carried by said stationary section, spring means associated with said lever arm and adjusting mem-.

ber and adapted to be actuated by the said adjusting member to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, and means for preventing further actuation of said spring means by said adjusting member when the said adjusting member reaches a predetermined position.

2. In a sash or store front construction, the

combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a lever arm carried by said movable section and having an opening therein, an adjusting member carried by said stationary section and adapted to be received within the opening in said ,lever arm, spring means associated with said lever arm and adjusting member and adapted to be actuated by the said adjusting member to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, and means for preventing further actuation of said spring means by said adjusting member when the said adjusting member reaches a predetermined position within the opening in said lever arm.

3. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a lever arm carried by said movable section and having an opening therein, an adjusting screw carried by said stationary section and adapted to be received within the opening in said lever arm, and spring means associated with said lever arm and adjusting screw and adapted to be actuated by the said adjusting screw to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, said adjusting screw being so related to the opening in said lever arm that further tightening of said adjusting screw will be automatically prevented when the said adjusting screw has actuated the said spring means to the desired extent.

4. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a lever arm carried by said movable section and having an opening therein, an adjusting screw carried by said stationary section and adapted to be received within the opening in said lever arm, and spring means associated with said lever arm and adjusting screw and adapted to be actuated by the said adjusting screw to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, the shape and size of said adjusting screw being so related to the shape and size of the opening in said lever arm that the said adjusting screw will be caused to automatically bind in said opening and thereby prevented from being further tightened when the said spring means has been actuated to the desired extent.

5. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a lever carried by said movable section and having a toothed portion, toothed means associated with said stationary section and engageable by the toothed portionof said lever, an adjusting member carried by said stationary section, spring means associated with said lever and adjusting member and adapted to be actuated by the said adjusting member to urge the said lever in a predetermined direction and the said movable section into engagement with the pane of glass, and means for preventing further actuation of said spring means by said adjusting member when the said adjusting member reaches a predetermined position.

6. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a lever carried by said movable section and having a toothed portion, toothed means associated with said stationary section and engageable by the toothed portion of said lever, said lever also having an opening therein, an adjusting member carried 'by said stationary section and adapted to be received within the opening in said lever, spring means associated with said lever and adjusting member and adapted to be actuated by the said adjusting member to urge the said lever in a predetermined direction and the said movable section into enr gagement with the pane of glass, and means for preventing further actuation of said spring means by said adjusting member when the said adjusting member reaches a predetermined position within the opening in said lever.

7. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a substantially L-shaped lever comprising a substantially vertical arm secured to said movable section and a substantially horizontal arm extending beneath the pane of glass toward the stationary section and having an opening therein, said vertical and horizontal arms being connected together by a toothed portion, toothed means associated with said stationary section and engageable by the toothed portion of said lever, a substantially vertical adjusting screw carried by said stationary section and having itslower end adapted to pass through the opening in said horizontal lever arm, and spring means associated with said lever and adjusting screw and adapted to be actuated by the said adjusting screw to urge the said lever in a predetermined direction and the said movable section into engagement with the pane of glass, said adjusting screw being so related to the opening in said horizontal lever arm that further tightening of said adjusting screw will be automatically prevented when the said adjusting screw has actuated the said spring means to the desired extent.

8. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetween, a substantially L-shaped lever comprising a substantially vertical arm secured to said movable section and a substantially horizontal arm extending beneath the pane of glass toward the stationary section and having an opening therein, said vertical and horizontal arms being connected together by a toothed portion, toothed means associated with said stationary section and engageable by the toothed portion of said lever, a substantially vertical adjusting screw carried by said stationary section and having its lower end adapted to pass through the opening in said horizontal lever arm, and a coil spring encircling said adjusting screw and bearing at its upper end against the said adjusting screw and at its lower end against said horizontal lever arm, said coil spring being compressed by the said adjusting screw upon tightening of the latter to urge the said lever in a predetermined direction and the said movable section into engagement with the pane of glass, the shape and size of said adjusting screw being so related to the shape and size of the opening in said horizontal lever arm that the said adjusting screw will be caused to automatically bind in said opening and thereby prevented from being further tightened when the said coil spring has been compressed to the desired extent.

9. In a sash or store front construction, the combination of a stationary section and a movable section adapted to receive and grip a pane of glass therebetwen, a substantially L-shaped lever comprising a substantialy vertical arm secured to said movable section and a substantially horizontal arm extending beneath the pane of glass toward the stationary section and having an opening therein, said vertical and horizontal arms being connected together by a toothed portion, toothed means asociated with said stationary section and engageable by the toothed portion of said lever, a substantially vertical adjusting screw carried by said stationary section and having its lower end adapted to pass through the opening in said horizontal lever arm, and a leaf spring secured at one end to said lever and having its opposite end extending rearwardly in spaced, substantially parallel relation to said horizontal lever arm and having an opening therein directly above the opening in the said lever arm, said adjusting screw being adapted upon tightening thereof to flex said spring to urge the said lever in a predetermined direction and the said movable section into engagement with the pane of glass, the shape and size of said adjusting screw being so related to the shape and size of the opening in said horizontal lever arm that the said adjusting screw will be caused to automatically bind in said opening and thereby prevented from being further tightened when the said spring has been flexed to the desired extent.

10. In a sash or store front construction, the combination with a stationary section and a movable section pivotally mounted upon said stationary section and cooperating therewith to grip a pane of glass therebetween, a lever arm fixed at one end to said movable section and having its opposite end extending beneath the pane of glass toward said stationary section, an adjusting member carried by said stationary section, spring means associated with said lever arm and adjusting member and adapted to be actuated by the said adjusting member to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, and means for preventing further actuation of said spring means by said adjusting member when the said adjusting member reaches a predetermined position.

11. In a sash or store front construction, the combination with a stationary section and a movable section pivotally mounted upon said stationary section and cooperating therewith to grip a pane of glass therebetween, a lever arm fixed at one end to said movable section and having its opposite end extending beneath the pane of glass toward said stationary section and provided with an opening, an adjusting member carried by said stationary section and adapted to be received within the opening in said lever arm, spring means associated with said lever arm and adjusting member and adapted to be actuated by the said adjusting member to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, and means for preventing further actuation of said spring means by said adjusting member when the said adjusting member reaches a predetermined position within the opening in said lever arm.

12. In a sash or store front construction, the combination with a stationary section and a movable section pivotally mounted upon said stationary section and cooperating therewith to grip a pane of glass therebetween, a lever arm fixed at one end to said movable section and having its opposite end extending beneath the pane of glass toward said stationary section and provided with an opening, an adjusting screw carried by said stationary section and having its inner end adapted to pass through the opening in said lever arm, and spring means associated with said lever arm and adjusting screw and adapted to be actuated by the said adjusting screw to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, said adjusting screw being so related to the opening in said lever arm that further tightening of said adjusting screw will be automatically prevented when the said adjusting screw has actuated the said spring means to the desired extent.

13. In a sash or store front construction, the combination with a stationary section and a movable section pivotally mounted upon said stationary section and cooperating therewith to grip a pane of glass therebetween, a lever arm fixed at one end to said movable section and having its opposite end extending beneath the pane of glass toward said stationary section and provided with an opening, an adjusting screw carried by said stationary section and having its inner end adapted to pass through the opening in said lever arm, and a coil spring encircling said adjusting screw and bearing at its upper end against the said adjusting screw and at its lower end against said lever arm, said coil spring being compressed by the said adjusting screw upon tightening of the latter to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, the shape and size of said adjusting screw being so related to the shape and size of the opening in said lever arm that the said adjusting screw will be caused to automatically bind in said opening and thereby prevented from being further tightened when the said coil spring has been compressed to the desired extent.

14. In a sash or store front construction, the combination with a stationary section and a movable section pivotally mounted upon said stationary section and cooperating therewith to grip a pane of glass therebetween, a lever arm fixed at one end to said movable section and having its opposite end extending beneath the pane of glass toward said stationary section and provided with an opening, an adjusting screw carried by said stationary section and having its inner end adapted to pass through the opening in said lever arm, and a leaf spring secured at one end to said lever arm and having its opposite end extending rearwardly in spaced, substantially parallel relation to said lever arm, said leaf spring having an opening therein directly above the opening in the said lever arm, said adjusting screw being adapted upon tightening thereof to flex said spring to urge the said lever arm in a predetermined direction and the said movable section into engagement with the pane of glass, the shape and size of said adjusting screw being so related to the shape and size of the opening in said lever arm that the said adjusting screw will be caused to automatically bind in said opening and thereby prevented from being further tightened when the said spring has been flexed to the desired extent.

CLYDE D. LOWRY. 

